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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-07-11 23:44:50 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-07-11 23:44:50 +0000
commit39acf453353a41a78fbc220360e884eb0eb33a59 (patch)
tree92344fe71153d61f64d744183d9c1006307fac3f /util-linux/switch_root.c
parente7067e38ea8c6e0e498270ee6e8cd6aa5e92796e (diff)
downloadbusybox-39acf453353a41a78fbc220360e884eb0eb33a59.tar.gz
busybox-39acf453353a41a78fbc220360e884eb0eb33a59.tar.bz2
switch_root: shrink
function old new delta switch_root_main 402 401 -1 rootdev 8 - -8 delete_contents 226 179 -47 ------------------------------------------------------------------------------ (add/remove: 0/1 grow/shrink: 0/2 up/down: 0/-56) Total: -56 bytes
Diffstat (limited to 'util-linux/switch_root.c')
-rw-r--r--util-linux/switch_root.c32
1 files changed, 11 insertions, 21 deletions
diff --git a/util-linux/switch_root.c b/util-linux/switch_root.c
index 1f6ec2dc7..21cc99229 100644
--- a/util-linux/switch_root.c
+++ b/util-linux/switch_root.c
@@ -9,9 +9,7 @@
#include "libbb.h"
#include <sys/vfs.h>
-
// Make up for header deficiencies.
-
#ifndef RAMFS_MAGIC
#define RAMFS_MAGIC ((unsigned)0x858458f6)
#endif
@@ -24,18 +22,16 @@
#define MS_MOVE 8192
#endif
-static dev_t rootdev;
-
// Recursively delete contents of rootfs.
-
-static void delete_contents(const char *directory)
+static void delete_contents(const char *directory, dev_t rootdev)
{
DIR *dir;
struct dirent *d;
struct stat st;
// Don't descend into other filesystems
- if (lstat(directory, &st) || st.st_dev != rootdev) return;
+ if (lstat(directory, &st) || st.st_dev != rootdev)
+ return;
// Recursively delete the contents of directories.
if (S_ISDIR(st.st_mode)) {
@@ -45,13 +41,13 @@ static void delete_contents(const char *directory)
char *newdir = d->d_name;
// Skip . and ..
- if (*newdir=='.' && (!newdir[1] || (newdir[1]=='.' && !newdir[2])))
+ if (DOT_OR_DOTDOT(newdir))
continue;
// Recurse to delete contents
- newdir = alloca(strlen(directory) + strlen(d->d_name) + 2);
- sprintf(newdir, "%s/%s", directory, d->d_name);
- delete_contents(newdir);
+ newdir = concat_path_file(directory, newdir);
+ delete_contents(newdir, rootdev);
+ free(newdir);
}
closedir(dir);
@@ -60,7 +56,6 @@ static void delete_contents(const char *directory)
}
// It wasn't a directory. Zap it.
-
} else unlink(directory);
}
@@ -70,15 +65,14 @@ int switch_root_main(int argc UNUSED_PARAM, char **argv)
char *newroot, *console = NULL;
struct stat st1, st2;
struct statfs stfs;
+ dev_t rootdev;
// Parse args (-c console)
-
opt_complementary = "-2"; // minimum 2 params
getopt32(argv, "+c:", &console); // '+': stop parsing at first non-option
argv += optind;
// Change to new root directory and verify it's a different fs.
-
newroot = *argv++;
xchdir(newroot);
@@ -90,7 +84,6 @@ int switch_root_main(int argc UNUSED_PARAM, char **argv)
// Additional sanity checks: we're about to rm -rf /, so be REALLY SURE
// we mean it. (I could make this a CONFIG option, but I would get email
// from all the people who WILL eat their filesystems.)
-
if (lstat("/init", &st1) || !S_ISREG(st1.st_mode) || statfs("/", &stfs)
|| (((unsigned)stfs.f_type != RAMFS_MAGIC) && ((unsigned)stfs.f_type != TMPFS_MAGIC))
|| (getpid() != 1)
@@ -99,24 +92,21 @@ int switch_root_main(int argc UNUSED_PARAM, char **argv)
}
// Zap everything out of rootdev
-
- delete_contents("/");
+ delete_contents("/", rootdev);
// Overmount / with newdir and chroot into it. The chdir is needed to
// recalculate "." and ".." links.
-
if (mount(".", "/", NULL, MS_MOVE, NULL))
bb_error_msg_and_die("error moving root");
xchroot(".");
xchdir("/");
// If a new console specified, redirect stdin/stdout/stderr to that.
-
if (console) {
close(0);
xopen(console, O_RDWR);
- dup2(0, 1);
- dup2(0, 2);
+ xdup2(0, 1);
+ xdup2(0, 2);
}
// Exec real init. (This is why we must be pid 1.)